Heat-treating furnace



S. T. BITTENBENDER ET AL HEAT TREATING FURNACE 1921 -2 Sheets-Sheet 1 Filed Aug. 30

llllll' l Patented Apr. 8, 1924.

UNITED STATES PATENT OFFICE.

SAMUEL THEODORE BITTENBENDER, BROOKLINE, AND JOHN G. ALLAN, O

QUINCY, MASSACHUSETTS.

HEAT-TREATING FURNACE.

Application filed August 30, 1921. Serial No. 496,830. I

To all whom it may concern: 7 71 Be it known that we, SAMUEL THEODORE BI'I'IENBENDER and JOHN G. ALLAN, citizens of the United States,-residing, respectively, at Brookline, in the county of Norfolk and State of Massachusetts, and at Quincy, in the county of Norfolk and State of Massae chusetts, have invented a new and useful Improvement in Heat-Treating Furnaces, of 10 which the following is a specification, like reference characters on the drawings indicating lik parts in the several figures This invention relates to furnaces designed especially for use in tempering, annealing, or otherwise heat treating metal bars or parts. e f i It isan important object of the invention to devise afurnace of this character in which the parts to be treated can be inserted in the furnace and removed therefrom more conveniently than in the usual types of furnaces. The invention also aims to devise a furnace construction which can be manufactured economically, which will be economical of fuel,will be adapted to manufacture in a variety of sizes, and which generally will meet the practical requirements of a furnace of this character. a g

' The nature of the invention will be readily understood'from' the following description when read inconnection with the accompanying. drawings, and the novel features will be particularly pointed out in the appended claims; V

Referring now to the drawings,. .7 Figure 1 is a-front elevation; partly in cross section, ofa furnace embodying the present invention; x 1 Fig.2 is an end view of the furnace inFigx l; p V

Fig. '3 is a verticalcross sectional view of the furnace shown in Figs. 1' and 2; and

Fig; 4 is a vertical, longitudinal, cross-sectional view of a portion ofthe furnace, taken on the line 4 4, Fig. 3. 1 The-construction shown comprises a lower section 2 and an ,uppersectionor arch 3. These parts maybe of anyzsuitable dimensions, but usuallyfthe length of-a furnace of this chara'cteris great comparedto its diameter, particularly when it is'to be used for the treatment of bars, rods, and the like.

Whilethe furnace may beof suitable shape, we prefer to make it in a 'substantially cylindrical form, as shown, and to divide this cylinder on a substantially horizontal plane located below the axis of the cylinder. Each. section, as shown, consists of a metal shell 4: reinforced by bars 5 of angular cross section These metal shells havea refractory lining which may consist of fire brick 7, the surface and joints of the brick being covered by a fireproof cement 8, such asthat commonly used in this trade. 7

A hearth 10, alsomade of fire brick, or

other refractory material, is supported hori zontally in the lowersection 2, this hearth resting on fire brick partitions 11. The

space below the hearth forms a combustion chamber which is divided bythe partitions llinto compartments 12. The gas or other fuel to. beburned is led into these compartments by pipes 13, these pipes leading from V a supply pipe or manifold ll to whichthe fuel mixture is supplied in any suitable man- 'ner. The gas burns in the compartments 12 of the combustion chamber andtthe gaseous products of combustion flow upwardly,

through a space 15provided at the back of the hearth, into the heating chamber 29.

These gases then flow over the hearth and circulate throughout the chamber; the products of combustion venting at the ends as indicatedby the arrows inFig. 1. The hearth 7 l0 isnotas long as the lower section 2 so that spaces ar provided at the opposite ends of the heart-h through, which these gases may .flow downwardly into flues 16-16tliat lead from" the opposite ends-0f the lower sec- .tion 2..

- .Thelower section ofthe furnaceiis suported. on brackets 18 spaced at'suitable in- .tervalslongitudinally of the furnace and thus is normally stationary. The upper section 3', however,-is mounted to swing'about a horizontal axis located at the back of the furnace and substantially on a level with the .upper surface of the hearth. F or" this purpose a series of small brackets 19 are secured to th rearward side of the upper section each having a cylindricalssurface to fi-tinto asemi-cylindrical socket formed in a bracket 20- that is secured to the lowersection 2. I

Any convenient mechanism may be provided for raising and lowering the upper section or arch 3, the construction shown consisting of two ropes or cables 21- 421 secured to the front of the arch and wound several times about a shaft 22 which is supported in bearings mounted on a frame 23 that overhangs the furnace. Each of these cables runs over a pulley 24 at the back of the frame and supports a counter-weight25. crank 26 is secured to the end of the shaft 22 and affords a convenient means for turning this shaft to raise or lower the front of the arch 3.

It will now be appreciated that by raising the arch or upper section 3, the furnace will be opened for its entire length, thus facili tating the placing and arranging of articles to be heat treated on the hearth 1'0 and their subsequent removal therefrom. These operations are further facilitated by placing the hearth on the same level with the front edge of the lower section of the furnace so that the heated articles may be rolled or placed on to and taken off the hearth and out of the furnace with relatively little effort. A further advantage of this construction is that it is very economical of fuel, due especially to the compact arrangement of the parts. It will also be evident that this furnace can be constructed .economically and that it lends itself conveniently to designs in either large or small units.

In order to enable the attendant to observe the progress of the heating operation and the condition of the materials being treated, a series of observation openings 27 are providcd in the front of the arch, each of these openings normally being closed a plug 28 of clay, fire brick or other suitable material.

While we have shown and described a furnace in which the arch is made as 'a unit, the arch may be made in two or more sections which can be raised and lowered separately or together. If a furnace embodying our invention is made of substantial length the making of the arch in sections may be advisable in order better to take care of contraction and expansion. Again under certain conditions it might prove advisable to divide the metal shell t transversely into sections, leaving the refractory lining as a unit. This construction is shown in Fig. 1 in which the shell is divided as indicated at 30.

While we have herein shown and described'the best embodiment of the invention 'ofwhich we areat'present aware, it will be appreciated that this embodiment may be modified as above suggested and in many other particulars without departing from the spirit or scope of this invention.

Having thus described our invention what we desire to claim as new is:

l. A furnace of the character described, comprising a lower section, a hearth supported in said section, said section having a combustion chamber therein below said hearth, and an arch cooperating with said section :to enclose the hearth and mounted for movement relative to said section to open the :side of the furnace for the lateral introduction or withdrawal of the charge.

'2. A furnace of the character described, comprising upper and lower furnace sections, a hearth supported in said lower section, the lower section having a combustion chamber therein below said hearth, means supporting the upper section for movement relative to the lower section to open the side of the furnace for the lateral introduction or withdrawal of the charge, and an observation opening in said upper section.

8. A furnace of the character described, comprising a lower section, a hearth mount ed therein, an arch shaped upper section pivotally mounted so that it may be raised or lowered to open or close said furnace.

'4. A furnace of the character described, comprising a stationary lower section, a hearth mounted horizontally in said section and having its upper surface substantially flushwith the front edge of said section, and an arch pivoted at the back of the furnace whereby .it maybe raised or lowered to openor close said furnace.

5; A furnace of the character described, comprising a substantially horizontal hearth,

a lower furnace section in which said hearth V I is mounted, said section having a combustion chamber therein below said hearth, fiues leading from the opposite ends of the furnace, an arch having a pivotal connection with said lower section at the rear thereof,

and means for raising and lowering the front of said arch to open or close the furnace.

6. A furnace of the character described, comprising a substantially horizontal hearth,

a lower furnace section in which said hearth is mounted, said section havmg a combustlon chamber therein below said hearth, pipe connections at 'the front of said furnace for conducting a fuel mixture into said chamber, fiues leading from the opposite ends of the furnace, an arch having a pivotal connection with said lower section at the back thereof, means for raisingand lowering said arch to open or close the furnace, said arch having observation openings therein, and means for normally closing said openings. 7. A furnace of substantially cylindrical form divided into upper and lower semicylindrical sections, a horizontal hearth sup ported in the lower section, said lower section having a combustion chamber therein below said hearth, means supporting said upper section for pivotal movement on a. horizontal axis located at the back of the furnace, and means for raising and lowering the front of said upper section to open or 5 close the furnace.

8. A furnace of the character described, comprising a substantially horizontal hearth and upper and lower furnace sections enclosing said hearth, each of said sections comprising a metal shell with a lining of refractory material, and said shells being divided transversely into sections.

In testimony whereof we have signed our names to this specification.

S. THEODORE BITTENBENDER. JOHN G. ALLAN. 

